Nearly a decade after a woman converted to Judaism, the beis din is considering revoking her conversion.

This woman was originally married to a non-Jew. Eventually they got divorced, and now she wants to marry a Jewish man. When applying for marriage the beis din discovered that during her original conversion period she was continuing her relationship with her non-Jewish boyfriend and she hid it from the beis din. She deceived the beis din and they will now look into the possibility of revoking her conversion.

The beis din stated that normally the rule of not looking into another beis din's conversions would not allow them to consider revoking the conversion, but in this case she herself told them that she deceived the original beis din regarding her relationship with the non-Jew. They must therefore redirect her back to the original beis din and look into what happened and investigate the conversion process in her case. In the meantime, she is being added to the list of people who cannot marry.
source: Israel Hayom

Obviously, some are upset about the fact that a beis din can possibly revoke a conversion nearly ten years after it happened. Converts should not have to walk around unsure if one day a beis din will say you are not Jewish.

And I agree with that. Once converted, converted. There are no backsies. A convert is as Jewish as any other Jew, and no matter what happens after the conversion, it cannot be taken back. The Shulchan Aruch even says if certain things were done improperly during the original conversion, the conversion remains valid. And, as well, the recent trend of rejecting some rabbis who do conversions as not doing them properly, despite being Orthodox rabbis, or not being knowledgeable enough or important enough to do conversions, is a crock. That does not fly in halacha and only works in Israel because the Rabbanut has been given centralized power to do such things.

This case seems to be different than that. In this case she seems to possibly have deceived the beis din doing the original conversion. If she deceived them it was not just regarding the intent of the conversion, which might still be ok after the fact, but in her actions. I dont know if the deception of hiding a non-Jewish boyfriend is strong enough to determine the original conversion invalid, but I can understand looking into it.

Converts should not need to walk around for years, for the rest of their lives, wondering if a rabbi will come over and question his or her Judaism. But converts should not be deceiving the beis din doing the conversion and sometimes that deception might need to be investigated.

----- UPDATE TO POST ------

It has been clarified to me that she did not deceive anyone in this case. The story is that she met a man in the conversion class with her and they decided to marry. He decided not to go through with the conversion. She did continue keeping kashrut.

As well, someone sent to me the tshuva of Rav Shaul Yisraeli, published by Eretz Chemda, that says even in a case of full deception and the convert never had any intention on keeping mitzvos, once the person has been converted, the conversion remains valid because they wanted to be part of the Jewish nation. Rav Yisraeli qualifies that by saying this is bdieved, and lechatchila we do not convert people who do not accept upon themselves to try to keep mitzvos as fully as possible. After the fact, the conversion remains valid and there is no such thing as revoking a conversion.

So, in light of this, in this case as well, her marriage should not be prevented and investigating her conversion is "honaas ha'ger"